Carpal tunnel syndrome affects approximately 3.7% of the general population and up to 7% of manual labor workers. Several varying surgical procedures are performed annually to treat patients with carpal tunnel syndrome. One of these surgical procedures is known as a carpal tunnel release procedure (“CTR procedure”). A primary goal of the CTR procedure is to cut a transverse carpal ligament in order to reduce median nerve compression and carpal tunnel pressures in the carpal tunnel region.
CTR procedures can be performed by accessing the carpal tunnel primarily from the outside or accessing the carpal tunnel primarily from the inside. In the former, a palmar incision of various sizes is used to directly visualize and transect the transverse carpal ligament. In the latter, the transverse carpal ligament is visualized from within the carpal tunnel using an endoscope advanced through a small palmar and/or distal wrist incision-endoscopic carpal tunnel release (ECTR).
One concern with CTR procedures is that it is hard to visualize the transverse carpal ligament and at-risk structures nearby (e.g., a median nerve and an ulnar artery). It is also hard to visualize individual anatomical variations in the carpal tunnel region. As a result, some CTR procedures can cause incomplete release of the transverse carpal ligament and others can cause injuries to the nearby at-risk structures.
In recent years, operators have used ultrasound guidance with CTR procedures to better visualize the carpal tunnel region during the procedure. However, even with the improved visualization of ultrasound, there are still concerns even with these procedures. One concern is that a sharp cutting instrument may be passed into the carpal tunnel without the ability to precisely control deployment of a sharp cutting instrument. Thus, the sharp cutting instrument presents a risk to both the patient and the operator. It would be desirable to provide an improved device that includes a sharp cutting instrument that is not exposed until the cutting of the transverse carpal ligament occurs.
Also, several operators use ultrasound guidance to place a sharp cutting instrument in position to cut the transverse carpal ligament but do not utilize ultrasound visualization during the actual cutting. In some cases, this is because the sharp cutting instruments require the use of two hands to perform the cutting. Thus, when operators perform the cutting, they are not able to continue holding the ultrasound probe during cutting. It would be desirable to provide an improved device that allows for an operator to continue using ultrasound guidance during cutting. It would also be desirable to provide a device that allows for an operator to use one hand while cutting, so that the opposite hand can hold an ultrasound probe or otherwise engage in providing ultrasound guidance.
Further, there is typically a very narrow space between the median nerve and the ulnar artery in the carpal tunnel. This narrow space is a “safe zone” in which the transverse carpal tunnel ligament can be cut without risk to the median nerve or ulnar artery. This space is variable from patient to patient and can be less than 3 millimeters in some patients. Consequently, placing a sharp cutting instrument in this region can expose a patient to risks of injury. It would also be desirable to provide a device that can expand the “safe zone” in a patient to reduce risks of injury.